Heat oil in a skillet over medium heat. Sauté chicken until golden, about 5 minutes. Drain. Add broth, wine or broth, garlic, salt and pepper to skillet; bring to a boil. Reduce heat; cover and simmer for about 20 minutes. Add tomatoes, peppers and mushrooms. Simmer, covered, for 15 minutes, until chicken is cooked through. Transfer chicken to a serving dish; cover to keep warm. In a small bowl, combine cornstarch, water and rosemary; stir into vegetable mixture. Cook and stir until thickened and bubbly; cook for an additional
2 minutes. Serve chicken over noodles or rice; spoon sauce over chicken. Serves 5.